a2abbdbf9a
This is just a draft. ``` for f in `find . -name '*.lean'`; do echo $f; gsed "/^import/s/\b\(.\)/\u\1/g" $f > tmp; gsed "/^Import/s/Import/import/g" tmp > $f; done ```
29 lines
752 B
Text
29 lines
752 B
Text
/-
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Copyright (c) 2019 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Authors: Leonardo de Moura
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-/
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prelude
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import Init.Data.Nat.Basic
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import Init.Data.Nat.Div
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import Init.Coe
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namespace Nat
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partial def bitwise (f : Bool → Bool → Bool) : Nat → Nat → Nat | n, m =>
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if n = 0 then (if f false true then m else 0)
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else if m = 0 then (if f true false then n else 0)
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else
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let n' := n / 2;
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let m' := m / 2;
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let b₁ := n % 2 = 1;
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let b₂ := m % 2 = 1;
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let r := bitwise n' m';
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if f b₁ b₂ then bit1 r else bit0 r
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@[extern "lean_nat_land"]
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def land : Nat → Nat → Nat := bitwise and
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@[extern "lean_nat_lor"]
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def lor : Nat → Nat → Nat := bitwise or
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end Nat
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